What Are Microbicides?

Microbicides are products being developed to reduce the spread of HIV and other sexually-transmitted diseases (STDs). Microbicides could come in many forms, including gels, creams, suppositories, films, lubricants, sponges, or vaginal rings. They could be used in the vagina or rectum.

How Would Microbicides Work?

Microbicides could work in different ways:

Killing or making germs such as bacteria and viruses inactive

Changing the condition of the woman's vagina or rectum to make infection less likely

Blocking infection by creating a barrier between the germ and the cells of the vagina or rectum

Preventing the germ from spreading after it has entered the body

Are Microbicides Currently Available?

No. Scientists are testing many products to see whether they help protect against infection with HIV and/or other STDs. Some of these products have proven safe enough in lab studies that they are now being tested in people. However, no safe and effective microbicide is currently available to the public.

What Is Happening in Microbicide Research?

Microbicides have been in development for the past 15 years. A number of studies conducted on the early products have failed to find an effective microbicide.

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However, there is hope that a new group of microbicides that contain HIV drugs will be more effective. Unlike earlier products, these newer microbicides do not have to be applied at the time of sex. They may be used daily as a gel or possibly as a vaginal ring, that may only need to be inserted once a month.

Promising results were reported in July 2010 from a large study called
CAPRISA 004. This study of 889 HIV-negative women in South Africa showed that
when women used a one percent gel version of the HIV drug Viread (tenofovir)
inside the vagina, two out of every five HIV infections were prevented. These
study results provide early proof that HIV drug-based microbicides, in
particular tenofovir gel, can help protect women against HIV.

The CAPRISA 004 study also showed that women who used the tenofovir one
percent gel had half as many infections caused by herpes simplex virus (HSV-2),
or genital herpes. This is important because people infected with HSV-2 are
more likely to get infected with HIV as well as to spread it to others.

Unfortunately, a similar study of tenofovir one percent vaginal gel among
over 5000 HIV-negative women in Uganda, South Africa, and Zimbabwe was not
successful. This study, called the VOICE study (MTN 003), was stopped in the
fall of 2011 because it did not work. However, the tenofovir gel appeared to be
safe, without major side effects.

The VOICE study was also looking at the effectiveness of taking two
different HIV drugs in pill form – Viread (tenofovir) and Truvada
(tenofovir/emtricitabine). The tenofovir pill was also stopped because it did
not work; however, the part of the study using the Truvada pill is continuing,
to see if it works.

There is another study being done now to measure the effectiveness of one
percent tenofovir vaginal gel in 1700 HIV-negative women in South Africa. This
is called the FACTS 001 study; its results are expected in the spring of 2014.
Researchers hope that the FACTS 001 study will help us understand why the
CAPRISSA study showed the gel worked and the VOICE study did not.

There is also hope that a vaginal ring containing an HIV drug can prevent
the spread of HIV. The ring is flexible and designed to be placed deep inside
the vagina against the cervix, where it stays for one month. The benefit of
using a vaginal ring compared to a vaginal gel is that women would not have to
insert the microbicide ring as often as the gel.

Two studies, the ASPIRE study (MTN 020) and the Ring Study (IPM 027), are
looking at a vaginal ring containing an HIV drug called dapivirine (a
non-nucleoside reverse transcriptase inhibitor) to prevent the spread of HIV.
The ASPIRE study is looking at the ring’s effects in over 3000 women from
Malawi, South Africa, Uganda, Zambia, and Zimbabwe. The Ring Study is looking
at the effect of the ring in 1650 women from Rwanda and South Africa. Results
from both studies are expected in 2015.

Other related ongoing studies include: (1) MTN 008, which is looking at the
safety of tenofovir one percent vaginal gel in pregnant and breastfeeding women
the US, and (2) safety studies of rectal tenofovir one percent gel.

This article was provided by The Well Project. Visit The Well Project's Web site to learn more about their resources and initiatives for women living with HIV. The Well Project shares its content with TheBody.com to ensure all people have access to the highest quality treatment information available. The Well Project receives no advertising revenue from TheBody.com or the advertisers on this site. No advertiser on this site has any editorial input into The Well Project's content.

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